/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you maynot use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicablelaw or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.phoenix.end2end;

import static org.apache.phoenix.query.QueryServicesOptions.UNLIMITED_QUEUE_SIZE;
import static org.apache.phoenix.util.TestUtil.TEST_PROPERTIES;
import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertFalse;
import static org.junit.Assert.assertTrue;
import static org.junit.Assert.fail;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.Map;
import java.util.Properties;
import java.util.concurrent.RejectedExecutionException;

import org.apache.phoenix.compile.ExplainPlan;
import org.apache.phoenix.compile.ExplainPlanAttributes;
import org.apache.phoenix.jdbc.PhoenixPreparedStatement;
import org.apache.phoenix.query.BaseTest;
import org.apache.phoenix.query.QueryServices;
import org.apache.phoenix.query.QueryServicesOptions;
import org.apache.phoenix.util.PropertiesUtil;
import org.apache.phoenix.util.ReadOnlyProps;
import org.apache.phoenix.util.TestUtil;
import org.junit.Before;
import org.junit.BeforeClass;
import org.junit.Test;
import org.junit.experimental.categories.Category;
import org.apache.phoenix.thirdparty.com.google.common.collect.Maps;

@Category(NeedsOwnMiniClusterTest.class)
public class QueryWithLimitIT extends BaseTest {
    
    private String tableName;
    private static Map<String,String> props = Maps.newHashMapWithExpectedSize(5);

    @BeforeClass
    public static synchronized void doSetup() throws Exception {
        // Must update config before starting server
        props.put(QueryServices.STATS_GUIDEPOST_WIDTH_BYTES_ATTRIB, Long.toString(50));
        props.put(QueryServices.QUEUE_SIZE_ATTRIB, Integer.toString(1));
        props.put(QueryServices.SEQUENCE_SALT_BUCKETS_ATTRIB, Integer.toString(0)); // Prevents RejectedExecutionException when creatomg sequence table
        props.put(QueryServices.THREAD_POOL_SIZE_ATTRIB, Integer.toString(4));
        props.put(QueryServices.LOG_SALT_BUCKETS_ATTRIB, Integer.toString(0)); // Prevents RejectedExecutionException when creating log table
    }

    @Before
    public void setupDriver() throws Exception {
        destroyDriver();
        setUpTestDriver(new ReadOnlyProps(props.entrySet().iterator()));
        tableName = generateUniqueName();
    }

    @Test
    public void testQueryWithLimitAndStats() throws Exception {
        Properties props = PropertiesUtil.deepCopy(TestUtil.TEST_PROPERTIES);
        Connection conn = DriverManager.getConnection(getUrl(), props);
        try {
            conn.createStatement().execute("create table " + tableName + "\n" +
                "   (i1 integer not null, i2 integer not null\n" +
                "    CONSTRAINT pk PRIMARY KEY (i1,i2))");
            initTableValues(conn, 100);
            
            String query = "SELECT i1 FROM " + tableName +" LIMIT 1";
            ResultSet rs = conn.createStatement().executeQuery(query);
            assertTrue(rs.next());
            assertEquals(0, rs.getInt(1));
            assertFalse(rs.next());
            
            ExplainPlan plan = conn.prepareStatement(query)
                .unwrap(PhoenixPreparedStatement.class).optimizeQuery()
                .getExplainPlan();
            ExplainPlanAttributes explainPlanAttributes =
                plan.getPlanStepsAsAttributes();
            assertEquals("SERIAL 1-WAY",
                explainPlanAttributes.getIteratorTypeAndScanSize());
            assertEquals("FULL SCAN ",
                explainPlanAttributes.getExplainScanType());
            assertEquals(tableName,
                explainPlanAttributes.getTableName());
            assertEquals("SERVER FILTER BY FIRST KEY ONLY",
                explainPlanAttributes.getServerWhereFilter());
            assertEquals(1, explainPlanAttributes.getServerRowLimit().intValue());
            assertEquals(1, explainPlanAttributes.getClientRowLimit().intValue());
        } finally {
            conn.close();
        }
    }
    
    @Test
    public void testQueryWithoutLimitFails() throws Exception {
        Properties connProps = PropertiesUtil.deepCopy(TestUtil.TEST_PROPERTIES);
        String query = "SELECT i1 FROM " + tableName;
        try (Connection conn = DriverManager.getConnection(getUrl(), connProps)) {

            conn.createStatement().execute("create table " + tableName + "\n" +
                    "   (i1 integer not null, i2 integer not null\n" +
                    "    CONSTRAINT pk PRIMARY KEY (i1,i2))");
            initTableValues(conn, 100);
            conn.createStatement().execute("UPDATE STATISTICS " + tableName);

            try {
                ResultSet rs = conn.createStatement().executeQuery(query);
                rs.next();
                fail();
            } catch (SQLException e) {
                assertTrue(e.getCause() instanceof RejectedExecutionException);
            }
        }

        // now run the same test with queue size set to unlimited
        try {
            destroyDriver();
            // copy the existing properties
            Map<String, String> newProps = Maps.newHashMap(props);
            newProps.put(QueryServices.QUEUE_SIZE_ATTRIB, Integer.toString(UNLIMITED_QUEUE_SIZE));
            setUpTestDriver(new ReadOnlyProps(newProps.entrySet().iterator()));
            try (Connection conn = DriverManager.getConnection(getUrl(), connProps)) {
                // now the query should succeed
                ResultSet rs = conn.createStatement().executeQuery(query);
                assertTrue(rs.next());
            }
        } finally {
            destroyDriver();
        }
    }

    protected void initTableValues(Connection conn, int nRows) throws Exception {
        PreparedStatement stmt = conn.prepareStatement(
            "upsert into " + tableName + 
            " VALUES (?, ?)");
        for (int i = 0; i < nRows; i++) {
            stmt.setInt(1, i);
            stmt.setInt(2, i+1);
            stmt.execute();
        }
        
        conn.commit();
    }

}
